To install Apache from the terminal, you can use the apt-get command with sudo. I.e.
sudo apt-get install apache2
Running the above command will ask us for our root password, since we are running it with sudo. The install part should be self-explanatory.
When it is done installing, you should be able to test if it works by entering http://localhost/ in your browser, a standard Apache page is shown if the server has successfully been installed.
If you later want to remove the Apache, simply replace the install part with remove. I.e.:
sudo apt-get remove apache2
Starting and Stopping the server
To start and stop the server, you can try using the following terminal commands.
sudo service apache2 start sudo service apache2 stop sudo service apache2 restart
In case the above commands are now working for you, try the below instead:
sudo /etc/init.d/apache2 start sudo /etc/init.d/apache2 stop sudo /etc/init.d/apache2 restart